The present application is directed towards multi-function intra-building communication systems and, more particularly, to a novel system for providing simultaneous security, communication and control functions within the periphery of a building.
Intra-building communication is often required to not only provide building security, by monitoring the periphery of the building for intruders, but also to inactivate, set, reset and monitor detection devices, such as smoke, gas and open-door/open-window detectors. Additional intra-building communications for the monitoring and control of lights and appliances, both to control power usage and the technical functions, is also highly desirable. Because such intra-building communications are desirably provided without causing interference to other electronic devices in th building, or in adjacent buildings, previous approaches to this problem, such as the addition of signal wires to the structure, use of power wiring for communications and radio transmission, have all been found to be somewhat less than optimum, due to respective problems in the difficulty and expense of adding additional wires to a building interior after the building has been constructed, the presence of power line interference, harmonics and transients when power line carrier communication is attempted, and radio transmission interference from signals originating at relatively large distances from the building to be monitored. It is known that magnetic induction, by means of a loop of wire formed about the building periphery, has potential for providing intra-building communication.